Conditioning metal surfaces before phosphating them

ABSTRACT

A highly effective and storage stable conditioning treatment for metal surfaces prior to phosphating them is a suspension in water containing solid miorosize particles of at least one phosphate of a divalent or trivalent metal and an accelerant selected from the group consisting of sacoharides and their derivatives thereof, orthophosphoric acid, condensed phosphoric acids, organophosphonic acids, and polymers of vinyl acetate and/or carboxylic acid. The surface conditioning liquid composition is used simply by effecting contact between the metal and the liquid composition, and can also be used to simultaneously carry out degreasing, particularly when the conditioning liquid also contains nonionic or anionic surfactant.

FIELD AND BACKGROUND OF THE INVENTION

This invention generally concerns the art of phosphate conversioncoating treatments that are executed on the surfaces of such metals asiron, steel, zinc-plated steel sheet, aluminum, and magnesium alloys.More specifically, the invention concerns a composition and process forconditioning metal surfaces prior to such conversion treatments in orderto accelerate the conversion reactions, shorten the treatment time, andmicrosize the phosphate coating crystals.

The formation of dense, microfine phosphate coating crystals isconsidered desirable both within the realm of automotive phosphatetreatments and within the realm of the phosphate treatments associatedwith plastic working. The formation of such a coating is considereddesirable in the former case in order to improve the post-paintingcorrosion resistance and in the latter case in order to reduce frictionduring pressing and extend the life of the press tool. In order toobtain dense, microfine phosphate coating crystals, a surfaceconditioning process is executed prior to the phosphate conversioncoating treatment, with a goal of activating the metal surface andproducing nuclei for deposition of the phosphate coating crystals. Thefollowing treatment sequence is a generalized example of the phosphateconversion coating processes used to produce dense, microfine phosphatecoating crystals:

(1) Degreasing;

(2) Tap water rinse (multistage);

(3) Surface conditioning;

(4) Phosphate conversion coating treatment;

(5) Tap water rinse (multistage);

(6) Purified water rinse.

The surface conditioning step is used to induce the formation of dense,microfine phosphate coating crystals. Compositions used for this purposeare known from, for example, U.S. Pat. Nos. 2,874,081, 2,322,349, and2,310,239, in which titanium, pyrophosphate ions, orthophosphate ions,and sodium ions are disclosed as the main constituent components in thesurface conditioning agent. These surface conditioning compositions,known as jernstedt salts, contain titanium ions and titanium colloid inaqueous solution.

The titanium colloid becomes adsorbed on the metal surface when thedegreased, water-rinsed metal is dipped in or sprayed with an aqueoussolution of the surface conditioning composition. The adsorbed titaniumcolloid forms nuclei for deposition of the phosphate coating crystals inthe ensuing phosphate conversion coating treatment and thereby supportsand induces an acceleration of the conversion reactions and amicrofine-sizing and densification of the phosphate coating crystals.The surface conditioning compositions currently in commercial use allemploy Jernstedt salts, but a number of problems have been associatedwith the use in surface conditioning processes of titanium colloidsobtained from Jernstedt salts.

A first problem is the timewise deterioration in the surfaceconditioning liquid composition. Aqueous solutions that have just beenprepared from the prior-art surface conditioning compositions are infact very effective in terms of microfine-sizing and densification ofthe phosphate coating crystals. However, within several days afterpreparation of the aqueous solution, these baths suffer from a loss ofactivity due to aggregation of the titanium colloid—regardless ofwhether or not the surface conditioning liquid composition has been usedduring this period of time. This loss of activity results in acoarsening of the phosphate coating crystals.

In order to deal with this problem, Japanese Laid Open (Kokai orUnexamined) Patent Application Number Sho 63-76883 (76,883/1988) hasdisclosed a method for maintaining and managing the surface conditioningactivity. In this method, the average particle size of the titaniumcolloid in the surface conditioning liquid composition is measured andthe surface conditioning liquid composition is continuously dischargedso as to maintain the average particle size below a specific constantvalue. In addition, surface conditioning composition is supplied in anamount sufficient to compensate for the amount discharged. While thismethod does make possible a quantitative management of the primaryfactor related to the activity of the surface conditioning liquidcomposition, it also requires the discharge of surface conditioningliquid composition in order to maintain the activity. Moreover, thismethod requires the discharge of large amounts of surface conditioningliquid composition in order to maintain the same liquid compositionactivity as in the initial period after preparation of the aqueoussolution. This creates issues with regard to the waste water treatmentcapacity of plants that employ this method, and as a result the activityis actually maintained through a combination of continuous discharge ofthe surface conditioning liquid composition and total renewal.

A second problem is that the activity and life of the surfaceconditioning liquid composition depend strongly on the quality of thewater used for surface conditioning liquid composition build up.Industrial water is typically used to build up surface conditioningbaths. However, as is well known, most industrial water containscationic components, e.g., calcium and magnesium, that make the water“hard”, and the content of this component varies as a function of thesource of the industrial water. It is known that the titanium colloidwhich is the main component of the prior-art surface conditioning bathscarries an anionic charge in aqueous solution and is maintained in anonsedimenting, dispersed state by the corresponding electricalrepulsive forces. When the cationic component in industrial water ispresent in a large amount, the titanium colloid is electricallyneutralized by the cationic component, so that the electrical repulsiveforces are no longer effective and the activity of the titanium colloidis thereby nullified due to the occurrence of aggregation andsedimentation.

The addition of condensed phosphates such as pyrophosphates to surfaceconditioning baths has been proposed in order to sequester the cationiccomponent and thereby maintain the stability of the titanium colloid.However, when added in large amounts to a surface conditioning liquidcomposition, the condensed phosphate reacts with the surface of thesteel sheet to form a coating, which results in the production ofconversion defects in the ensuing phosphate conversion coatingtreatment. Finally, in localities that suffer from very high magnesiumand calcium concentrations, the surface conditioning liquid compositionmust be built up and supplied with water using pure water, which is veryuneconomical.

A third problem involves the temperature and pH conditions that must beused during the surface conditioning process. Specifically, surfaceconditioning activity cannot be generated at a temperature in excess of35° C. and a pH outside 8.0 to 9.5 due to aggregation of the titaniumcolloid. This has necessitated the use of very specific temperatures andpH ranges when using the prior-art surface conditioning compositions.This has also made it impossible to achieve cleaning and activation ofmetal surfaces on a long-term basis using a single liquid compositionformulated by the addition of surface conditioning composition to adegreaser.

A fourth problem is the lower limit on the microfine-sizing of thephosphate coating crystals that can be obtained through the activity ofthe surface conditioning liquid composition. The surface conditioningactivity is obtained by the adsorption of the titanium colloid on themetal surface to form nuclei for deposition of the phosphate coatingcrystals. Thus, finer, denser phosphate coating crystals will beobtained as larger numbers of colloidal titanium particles becomeadsorbed on the metal surface during the surface conditioning process.

From this one might at first draw the conclusion that the number oftitanium colloid particles in the surface conditioning liquidcomposition should simply be increased, i.e., that the concentration ofthe titanium colloid should be raised. However, when this concentrationis increased, the frequency of collisions among the colloidal titaniumparticles in the surface conditioning liquid composition is alsoincreased, and these collisions cause aggregation and precipitation ofthe titanium colloid. At present the upper limit on the usable titaniumcolloid concentration is ≦100 parts per million by weight, hereinafterusually abbreviated as “ppm”, and it has been impossible in the priorart to obtain additional microfine-sizing of phosphate coating crystalssimply by increasing the titanium colloid concentration beyond thislevel.

These problems have resulted in the appearance of methods that usesurface conditioning agents other than Jernstedt salts. For example,Japanese Laid Open (Kokai or Unexamined) Patent Application Numbers Sho5-156778 (156,778/1981) and Sho 57-23066 (23,066/1982) disclose surfaceconditioning methods in which the surface of steel strip ispressure-sprayed with a suspension containing the insoluble phosphatesalt of a divalent or trivalent metal. However, since these methodsmanifest their effects only when the suspension is pressure-sprayedagainst the workpiece, they often cannot be used for surfaceconditioning in existing phosphate conversion coating treatment plantswhere this surface conditioning is carried out by ordinary dipping orspraying.

Japanese Published Patent Application (Kokoku or Examined) Number Sho40-1095 (1,095/1965) has disclosed a surface conditioning method inwhich zinc-plated steel sheet is immersed in a very concentratedsuspension of the insoluble phosphate salt of a divalent or trivalentmetal. The working examples provided for this method are limited tozinc-plated steel sheet and have to use very high concentrations ofinsoluble phosphate salt of at least 30 grams per liter, hereinafterusually abbreviated as “g/L”, at a minimum in order to obtain surfaceconditioning activity.

In sum, then, notwithstanding the various problems associated withJernstedt salts and the various tactics that have been proposed fordealing with these problems, up to now there has yet to appear atechnology capable of replacing the use of Jernstedt salts in practicalphosphating operations.

The present invention seeks to solve at least one of the problemsdescribed hereinabove for the prior art and takes as its object theintroduction of a novel, highly time-stable surface conditioning liquidcomposition and process that can be used to achieve at least one of anacceleration of the conversion reactions, a shortening of the treatmenttime in phosphate conversion coating treatments, and inducement ofmicrofine-sized phosphate coating crystals.

BRIEF SUMMARY OF THE INVENTION

The inventors discovered that solid divalent or trivalent metalphosphate powder of a particular size and concentration (i) will adsorbonto the surface of a metal workpiece in an aqueous solution thatcontains a particular accelerant component to form nuclei for theensuing deposition of phosphate coating crystals and (ii) will provideadditional improvements in the reaction rate of the phosphate conversiontreatment. The major compositional invention accordingly is a surfaceconditioning liquid composition that characteristically contains atleast one phosphate powder selected from phosphates that contain atleast one divalent and/or trivalent metal and are sufficiently low inwater solubility to remain in the solid state when dispersed as a finepowder in the surface conditioning liquid composition and also containsas accelerant component at least one selection from the group consistingof the following subgroups:

(1) monosaccharides, polysaccharides, and derivatives thereof;

(2) orthophosphoric acid, condensed phosphoric acids, andorganophosphonic acid compounds;

(3) water-soluble polymers that are homopolymers or copolymers of vinylacetate and derivatives of these homopolymers and copolymers;

(4) copolymers and polymers as afforded by the polymerization of:

(a) at least one selection from:

monomers, exclusive of vinyl acetate, that conform to general chemicalformula (I):

 where R¹=H or CH₃ and R²=H, C₁ to C₅ alkyl, or C₁ to C₅ hydroxyalkyl;and

other α,β-unsaturated carboxylic acid monomers; and, optionally,

(b) not more than 50% by weight of monomers that are not vinyl acetateand are not within the description of part (a) immediately above but arecopolymerzable with said monomers that are within the description ofsaid part (a).

DETAILED DESCRIPTION OF THE INVENTION AND ITS PREFERRED EMBODIMENTS

The total accelerant component selected from immediately previouslyrecited subgroups (1) to (4) preferably has a concentration from 1 to2,000 ppm in said surface conditioning liquid composition.

The aforesaid phosphate powder preferably includes particles with sizesno greater than 5 micrometers, hereinafter usually abbreviated as “μm”,and independently is preferably present at a concentration from 0.001 to30 g/L, more preferably at least, with increasing preference in theorder given, 0.01, 0.10, 0.30, 0.50, 0.70, 0.90, or 0.99 g/L. Moreoverand independently, the divalent and/or trivalent metal present thereinis preferably at least one selection from Zn, Fe, Mn, Ni, Co, Ca, andAl.

In a preferred embodiment said surface conditioning liquid compositionalso contains alkali metal salt, ammonium salt, or a mixture of alkalimetal salt and ammonium salt. This alkali metal salt or ammonium salt ispreferably at least one selection from orthophosphate salts,metaphosphate salts, orthosilicate salts, metasilicate salts, carbonatesalts, bicarbonate salts, nitrate salts, nitrite salts, sulfate salts,borate salts, and organic acid salts and independently is preferablypresent at a concentration of 0.5 to 20 g/L.

A process according to the present invention for conditioning metalsurfaces prior to the phosphate conversion coating treatment thereofcharacteristically comprises effecting contact between the metal surfaceand a surface conditioning liquid composition according to the inventionas described above.

The surface conditioning liquid composition according to the presentinvention has a much better high-pH stability and high-temperaturestability than the colloidal titanium of the prior art and as aconsequence, through the addition to this liquid composition of alkalibuilder plus nonionic or anionic surfactant or mixture thereof, can alsobe used in a process for simultaneously executing degreasing and surfaceconditioning in which the metal surface is both cleaned and activated.

An example is provided below of the separate operations of a phosphateconversion coating treatment in which the surface conditioning liquidcomposition according to the present invention is used for degreasingand surface conditioning in a single process operation:

(1) degreasing and surface conditioning in a single process operation;

(2) phosphate conversion coating treatment;

(3) tap water rinse (multistage); and

(4) pure water rinse.

The use of the surface conditioning liquid composition according to thepresent invention to effect degreasing and surface conditioning in asingle process operation makes possible omission of the water rinse stepbetween degreasing and surface conditioning—a feature heretoforeunavailable in the prior art. Moreover, since the surface conditioningliquid composition according to the present invention can be used over abroad pH range and can tolerate the addition of various alkali metalsalts, the degreasing and surface conditioning in a single processoperation that is identified as process operation (1) above can bepreceded by a preliminary cleaning or a preliminary degreasing dependingon the particular surface contamination status of the metal workpiece.

The essential components in the present invention are the accelerantcomponent and the metal phosphate powder selected from phosphates thatcontain at least one divalent and/or trivalent metal (hereinafterusually abbreviated simply as the “phosphate powder”). This phosphatepowder, being a component that is the same as or similar to that inphosphate conversion baths and phosphate conversion coatings, will notnegatively affect the phosphate conversion liquid composition even whencarried over thereinto. Another advantage to this phosphate powder isthat it also does not negatively affect the performance of the phosphateconversion coating even when taken into the phosphate conversion coatingthrough formation of the nuclei in the phosphate conversion coating. Thefollowing can be provided as examples of the phosphate powder used bythe present invention: Zn₃(PO₄)₂, Zn₂Fe(PO₄)₂, Zn₂Ni(PO₄)₂, Ni₃(PO₄)₂,Zn₂Mn(PO₄)₂, Mn₃(PO₄)₂, Mn₂Fe(PO₄)₂, Ca3(PO₄)₂, Zn₂Ca(PO₄₎ ₂, FePO₄,AlPO₄, CoPO₄, Co₃(PO₄)₂, sufficiently water insoluble hydrates of all ofthese phosphate salts.

The particle size of the phosphate powder used in the present inventionis preferably not more than, with increasing preference in the ordergiven, 5.0, 4.0, 3.5, 3.0, 2.5, 20, or 1.7 μm in order to also induce astable dispersion of the insoluble material in the aqueous solution. Atthe same time, however, the presence in the surface conditioning liquidcomposition of the present invention of additional phosphate powder withparticle sizes greater than 5 μm has no adverse influence whatever onthe advantageous effects of the present invention, which will appearonce the concentration of ≦5 μm microparticles in the surfaceconditioning liquid composition reaches a certain concentration.

The desired particle size, and possibly other desirable characteristics,of the solid phosphate power used in a composition according to theinvention, are readily and therefore preferably obtained by grinding,most preferably ball milling, a suspension of the solid phosphate inwater in which an accelerant component as defined above is dissolveduntil the desired particle size is achieved. If a ball mill is used, theballs are preferably of a very hard ceramic, most preferably zirconia,and independently preferably have a diameter that is not more than, withincreasing preference in the order given, 5, 3, 2.0, 1.5, 1.0, 0.80,0.70, 0.60, or 0.50 millimeters.

Not only does the phosphate powder used in the present invention formnuclei for deposition of the phosphate crystals, this powder alsofunctions to accelerate the deposition reactions. The concentration ofthe phosphate powder is preferably from 0.001 to 30 g/L in order to formnuclei for phosphate crystal deposition and accelerate the initialphosphate crystal deposition reactions. A phosphate powder concentrationless than 0.001 g/L (i) can not satisfactorily accelerate the initialphosphate crystal deposition reactions, because of the correspondinglysmall amount of phosphate powder adsorbed on the metal surface and (ii)also will not satisfactorily accelerate the reactions due to thecorrespondingly small number of divalent or trivalent metal phosphateparticles functioning as nuclei. A phosphate powder concentration inexcess of 30 g/L is simply uneconomical, because no additionalacceleration of the phosphate conversion reactions is obtained atconcentrations above 30 g/L.

The present inventors discovered that surface conditioning activityappears in the presence of any of the accelerant components of thepresent invention as described herein, even when treatment is carriedout by dipping at low concentrations of the phosphate powder and withoutthe application of any physical force to the metal surface that isgreater than the force supplied by conventional process operations, suchas dipping, stirring, spraying, pumping, or the like that areconventionally used with prior art titanium colloidal activators, Thepresent invention operates simply through contact between the workpieceand the surface conditioning liquid composition and thus operates on areaction mechanism that is entirely different from that of the prior artthat requires robust physical force to accelerate solid phosphate saltparticles into the surface being conditioned.

The concentration of the accelerant component in the composition ispreferably from 1 to 2,000 ppm. At concentrations below 1 ppm asatisfactory surface conditioning activity usually can not be producedby simple contact between the metal workpiece and the surfaceconditioning liquid composition. Not only can no additional effects beexpected at concentrations in excess of 2,000 ppm, but suchconcentrations may result in an excessive adsorption by the accelerantcomponent on the surface of the metal workpiece and hence hinder thephosphate conversion activity.

The basic structural unit saccharide of the monosaccharides,polysaccharides, and derivatives thereof used as accelerants in thepresent invention can be selected from, for example, fructose, tagatose,psioose, sofbose, erythrose, threose, ribose, arabinose, xylose, lyxose,allose, altrose, glucose, mannose, gulose, idose, galactose, and talose.(For the purposes of the present invention, a substance that producestwo or more saccharide units by hydrolysis of each molecule isdesignated as a polysaccharide and a saccharide that itself can not behydrolyzed further to produce a lower molecular weight saccharide isdesignated as a monsaccharide.)

In the case of the monosaccharides, the basic structural saccharidesdescribed above will be used as such; in the case of thepolysaccharides, homolysaccharides or heteropolysaccharides of theaforementioned basic structural saccharides can be used; finally,derivatives of the preceding can be afforded by the substitution of thehydrogen atom of at least one of the hydroxyls in the basic saccharideby a substituent moiety such as —NO₂, —CH₃, —C₂H₄OH, —CH₂CH(OH)CH₃, and—CH₂COOH. Combinations of several species of monosaccharides,polysaccharides, and derivatives thereof can also be used.

The advantageous effects of the invention are independent of theconfiguration and optical rotation of the basic structural saccharideand the invention can therefore use any combination of D-monosaccharidesand L-monosaccharides and both dextrorotatory and levorotatory opticalrotations. Nor will any problem be created by the use of the sodium orammonium salt of the aforementioned monosaccharides, polysaccharides,and derivatives thereof in order to improve the water solubility ofsame. Moreover, when the preceding structures are poorly soluble inwater, they can be used after preliminary dissolution in an organicsolvent that is miscible with water.

Examples of suitable accelerant component substances from theabove-described subgroup (2) are: pyrophosphoric acid, tripolyphosphoricacid, trimetaphosphoric acid, tetrametaphosphoric acid,hexametaphosphodc acid, aminotrimethylenephosphonic acid,1-hydroxyethylidene-1,1-diphosphonic acid,ethylenediaminetetramethylenephosphonic acid,diethylenetriaminepentamethylenephosphonic add, and the sodium andammonium salts of the preceding, and the sodium and ammonium salts ofany of the preceding acids in this sentence. The invention can use asingle selection or any combination thereof.

Subgroup (3) of suitable accelerant components as described above areexemplified by polyvinyl alcohols afforded by the hydrolysis of vinylacetate polymers, cyanoethylated polyvinyl alcohols afforded by thecyanoethylation of such polyvinyl alcohols with acrylonitrile,formalated polyvinyl alcohols afforded by the acetalation of suchpolyvinyl alcohols with formaldehyde, urethanized polyvinyl alcoholsafforded by the urethanation of such polyvinyl. alcohols with urea, andwater-soluble polymer compounds afforded by the introduction of thecarboxyl group, sulfonic group, or amide group into polyvinyl alcohol.Monomers copolymerized with vinyl acetate can be exemplified by acrylicadd, crotonic acid, and maleic anhydride. The beneficial effectsassociated with the present invention will be fully manifested as longas the vinyl acetate polymers or derivatives thereof and/or thecopolymers of vinyl acetate and monomers copolymerizable therewith aresufficiently soluble in water. As a result, these effects areindependent of the degree of polymerization and degree of functionalgroup introduction of the subject polymers. The invention can use asingle selection from the above-described polymers and copolymers or canuse any combination thereof.

In connection with subgroup (4) as defined above of suitable accelerantsubstances:

monomers that conform to general chemical formula (I) can be exemplifiedby methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate,pentyl acrylate, methyl methacrylate, ethyl methacrylate, propylmethacrylate, butyl methacrylate, pentyl methacrylate, hydroxymethylacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutylacrylate, hydroxypentyl acrylate, hydroxymethyl methacrylate,hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutylmethacrylate, and hydroxypentyl methacrylate; The α,β-unsaturatedcarboxylic acid monomers other than acrylic and methacrylic acids can beexemplified by maleic acid and crotonic acid;

monomers copolymerizable with the preceding monomers can be exemplifiedby styrene, vinyl chloride, and vinylsulfonic acid;

the invention can use polymer synthesized by the polymerization of asingle monomer from among the preceding or copolymer synthesized by thepolymerization of any combination of the preceding monomers.

The surface conditioning liquid composition according to the presentinvention can also contain an alkali metal salt or ammonium salt or amixture thereof. Suitable alkali metal salts and ammonium salts areexemplified by orthophosphate salts, metaphos phate salts, orthosilicatesalts, metasilicate salts, carbonate salts, bicarbonate salts, nitratesalts, nitrite salts, sulfate salts, borate salts, and organic acidsalts. The invention can also use combinations of two or more selectionsfrom the aforesaid alkali metal and ammonium salts.

The alkali metal and ammonium salts used by the present invention ingeneral will be equivalent to the alkali builders used in commercialcleaning agents. As a consequence, the activities associated with thealkali builders in commercial cleaning agents, i.e., the ability tosoften hard water and cleaning activity with respect to oil, willprovide activity as a cleaning agent as well as additional improvementsin the liquid composition stability of the surface conditioning liquidcomposition used by the present invention.

The concentration of the alkali metal salt or ammonium salt is desirablyfrom 0.5 to 20 g/L. The hard water softening activity and cleaningactivity will not usually be satisfactory at concentrations below 0.5g/L, while concentrations in excess of 20 g/L are simply uneconomicalbecause no additional benefits are obtained at such concentrations.

Unlike the prior-art technologies, the surface conditioning liquidcomposition according to the present invention has the ability to retainits effects and activities in almost any use environment. Thus, thepresent invention provides at least one, and in favorable instances all,of the following advantages over the prior art-technologies:

(1) higher time-wise stability;

(2) less deterioration in conditioning activity when hardness componentssuch as Ca and Mg increase in concentration in the liquid composition;

(3) ability to be used at higher temperatures;

(4) ability to be mixed with various alkali metal salts withoutsubstantial reduction in its conditioning activity; and

(5) higher stability over a wider pH range.

The liquid composition according to the present invention can thereforebe used to carry out degreasing and surface conditioning in a singleprocess operation, although prior-art technologies have been unable tocontinuously maintain stable qualities in this type of use. In additionto the above-described alkali metal or ammonium salts, the liquidcomposition according to the present invention can also tolerate theaddition of other known inorganic alkali builders, organic builders, andsurfactants for the purpose of improving the cleaning performance insuch a degreasing +surface conditioning in a single process operation.Moreover, irrespective of the execution of degreasing and surfaceconditioning in a single process operation, a known sequestering agentand/or condensed phosphate can be added in order to mitigate any adverseinfluence of cationic component carried over into the surfaceconditioning liquid composition.

A surface conditioning process according to the present invention may becarried out simply by effecting contact between the metal surface and asurface conditioning liquid composition according to the invention asdescribed above; such factors as the contact time and temperature of thesurface conditioning liquid composition are not usually critical.Furthermore, the surface conditioning process according to the presentinvention can be applied to any metal on which phosphate treatment isexecuted, e.g., iron and steel, zino-plated steel sheet, aluminum,aluminum alloys, and magnesium alloys.

The phosphate conversion treatment executed after the surfaceconditioning treatment according to the present invention can employ anymethodology, e.g., dipping, spraying, electrolysis, and the like. Theparticular phosphate coating deposited is not critical as long as it isa phosphate conversion coating, e.g., a zinc phosphate, manganesephosphate, or calcium/zinc phosphate conversion coating.

The use of a surface conditioning liquid composition according to thepresent invention will be described in greater detail below throughworking and comparative examples. The phosphating treatment used in theexamples is a zinc phosphating treatment for underpaint applications,but this treatment is provided simply as one example of phosphatingtreatments and in no way limits the applications of the surfaceconditioning liquid composition of the present invention.

Substrates

The designations and properties of the sample sheets used as thesubstrate surface treated In the working and comparative examples wereas follows (“JIS” means “Japanese Industrial Standard” and “g/m²” means“grams per square meter”):

SPC (cold-rolled steel sheet according to JIS G-3141);

EG (steel sheet electrogalvanized on both surfaces, with zinc add-onweight of 20 g/m²);

GA (steel sheet, hot-dip galvannealed on both surfaces, with zinc add-onweight=45 g/m²);

Zn—Ni (steel sheet, Zn/Ni alloy electroplated on both surfaces, platingweight=20 g/m²);

Al (aluminum sheet according to JIS 5052); and

MP (magnesium alloy sheet according to JIS H-4201).

Process Operation Sequence

Each of the sample sheets was treated using the following sequenceunless otherwise explicitly noted: alkaline degreasing→waterrinse→surface conditioning treatment→formation of zinc phosphatecoating→water rinse→rinse with deionized water.

In both the working and comparative examples, the alkaline degreasingused a 120 second spray at 42° C. of a solution of FINECLEANER® L4460concentrate (a commercial product of Nihon Parkerizing Co., Ltd.) thathad been diluted with tap water to 2% of the concentrate.

The surface conditioning treatment was run by dipping the workpiece inthe particular surface conditioning liquid composition described belowin each of the working and comparative examples.

In order to form the zinc phosphate coating, in both the working andcomparative examples PALBOND® L3020 concentrate (a commercial product ofNihon Parkerizing Co., Ltd.) was diluted with tap water to 4.8% and thecomponent concentrations, total acidity, free acidity, and accelerantconcentration were adjusted to the concentrations currently in generaluse for automotive zinc phosphate treatments. The resulting liquidcomposition was contacted with the substrates by dipping them into thesurface conditioning liquid composition for 120 seconds at 42° C.

Both the tap water rinse and the pure water rinse used a 30-second sprayat room temperature.

Tests for Evaluating the Zinc Phosphate Coatings

The coating appearance (“CA”), coating weight (“CW”), coating crystalsize (“CS”), and (only on the SPC substrates) the “P ratio” weremeasured, by the methods described immediately below, on the zincphosphate coatings formed after the surface conditioning treatment.

Coating appearance (CA): the presence/absence of coating voids andnonuniformity was evaluated visually and was scored on the followingscale:

++: uniform. good-quality appearance;

+: nonuniform in some regions, but with no visually apparent voids;

Δ: presence of some minor voids along with nonuniformity;

×: substantial area fraction of voids; and

××: no conversion coating present.

Coating weight (CW): The weight of the sample sheet was measured afterformation of the zinc phosphate coating to give the value W1 (in grams,hereinafter usually abbreviated as “g”). The zinc phosphate coating wasthen stripped (stripping liquid composition and conditions given below)and the weight was again measured to give W2 (also in g). The coatingweight was calculated from the following equation:

coating weight (g/m²)=(W1−W2)/(surface area).

For the cold-rolled steel sheets the stripping liquid was 5% chromicacid (i.e., CrO₃) solution in water, and the stripping conditions were75° C., 15 minutes, by dipping. For the galvanized steel sheet thestripping liquid composition was a solution containing 2% by weight ofammonium dichromate, 49% by weight of 28% by weight ammonia solution inwater, and 49% by weight of pure water, and the stripping conditionswere ambient temperature (i.e., 18-23° C.), 15 minutes, by dipping.

For the magnesium alloy and aluminum: The amount of elemental phosphorusin the zinc phosphate coating was quantitated using an X-ray fluorescentanalyzer and the add-on weight of the coating was calculated from the Pcontent, assuming that the coating was hopeite.

Coating crystal size (CS): The crystal size was determined by inspectionof an image of the zinc phosphate coating obtained using a scanningelectron microscope (“SEM”) at 1,500 times magnification.

“P ratio”: This value was determined by measuring the X-ray intensity ofthe phosphophyllite crystals (“P”) and the X-ray intensity of thehopeite crystals (“h”) in the zinc phosphate coating, using an x-raydiffraction instrument. The “P ratio” was calculated from the followingequation, using the thus obtained x-ray intensity values: “Pratio”=p/(p+h).

Table 1 reports the compositions of surface conditioning baths providedas examples of Claim one of the present invention, Table 2 reports thecompositions of the various surface conditioning baths provided ascomparative examples (including some with details explained below). Themonosaccharides, polysaccharides, and derivatives thereof used in theworking and comparative examples were commercial products obtained from,for example, Daicel Kagaku Kogyo Kabushiki Kaisha, Dai-ichi KogyoSeiyaku Kabushiki Kaisha, Asahi Kasei Kogyo Kabushiki Kaisha, andDainippon Seiyaku Kabushiki Kaisha. This component was selected takinginto account such factors as the type of basic structural saccharide,degree of polymerization, substituents, and degree of substitution. Thesubstituents are exemplified for the case of glucose, a basic structuralsac charide, using the following chemical structure:

TABLE 1 Component Type and Details Example 1 Example 2 Example 3 Example4 Example 5 Phosphate Salt Chemical PHOS PHOS PHOS PHOS PHOSConcentration, g/L 1.0 1.0 1.0 1.0 1.0 Particle Size, μm 0.5 0.5 0.5 0.50.5 Monosaccharide, Base Monosaccharide(s) Glucose Glucose GlucoseGlucose Fructose Polysaccharide, Substituent(s) —CH₂COOH, —CH₂COOH,—CH₂CO^(OH) None None or Derivative —NO₂ —NO₂ Thereof Degree ofSubstitution ≦1.8 ≦1.8 0.7 0 0 Degree of Polymerization ≦3,000 ≦3,000≦100 1 ≦100 Concentration, ppt 0.005 1.0 0.010 2.0 2.0 Alkali SaltChemical None None NaNO₂ MgSO₄.7H₂O None Concentration, g/L None None0.5 0.5 None Surfactant Chemical None None None None None Concentration,g/L None None None None None Treatment Temperature, ° C. 20 20 20 20 20Conditions Time, Seconds 30 30 30 30 30 Component Type and DetailsExample 6 Example 7 Example 8 Example 9 Example 10 Phosphate SaltChemical PHOS ZPTH ZPTH SCHO SCHO Concentration, g/L 1 1 1 10 5.0Particle Size, μm 0.5 0.6 1.2 0.4 0.4 Monosaccharide, BaseMonosaccharide(s) Glucose, Glucose Glucose Glucose GlucosePolysaccharide, Xylose, and or Derivative Galactose ThereofSubstituent(s) None —CH₂CO^(OH) —C₃H₆OH, —C₂H₄OH None —CH₃ Degree ofSubstitution 0 ≧2 1.9 1.0 0 Degree of Polymerization ≦500 ≦200 ≦1,000≦2,000 ≦500 Concentration, ppt 0.100 0.100 0.001 0.010 0.005 Alkali SaltChemical None None Na₂SiO₃.5H₂O Na₂CO₃ Na₃PO₄.12H₂O Concentration, g/LNone None 5.0 1.0 10 Surfactant Chemical None None None None (EO)₁₁NPEConcentration, g/L None None None None 2.0 Treatment Temperature, ° C.20 20 20 20 40 Conditions Time, Seconds 30 30 30 30 120 NewAbbreviations in Table 1 “PHOS” means “phosphophyllite”; “ZPTH” means“Zn₃(P^(O) ₄)₂.4^(H) ₂O”; “SCHO” means “^(scholzite)”; “^((EO)) ₁₁NPE”means “a surfactant made by ethoxylating nonyl phenol to add an averageof 11 ethylene oxide residues per molecule”; “ppt” means ”parts perthousand by weight”.

In the case of glucose, the 3 hydroxyls at R¹, R², and R³ can beetherified. In the examples under consideration, the type of substituentand degree of substitution (number of hydroxyl groups that have beensubstituted by the substituent(s) per unit of the basic structuralsaccharide) were varied in order to investigate the correspondingeffects. The polysaccharide, or derivative thereof. In the ageing test,the surface conditioning liquid composition was allowed to stand for 10days at room temperature after preparation and was then used.

EXAMPLE 1

A precipitate was produced by alternately adding 100 milliliters(hereinafter usually abbreviated as “mL”) of a zinc sulfate solutionthat contained 1.0 mole/liter (hereinafter usually abbreviated as“mol/L”) of zinc sulfate in water as a solvent and 100 mL of a 1.0 mol/Lsolution of sodium monohydrogen phosphate in water to one liter of a 0.5mol/L solution of iron (II) sulfate in water heated to 50° C. Theprecipitate-containing aqueous solution was heated for one hour at 90°C. in order to ripen the precipitate particles, after

TABLE 2 Component Type and Details CE 1 CE 2 CE 3 CE 4 CE 5 CE 6 CE 7Phosphate Salt Chemical PL-ZN PL-ZN PHOS PHOS PHOS PHOS PHOSConcentration, g/L 1.0 1.0 1.0 1.0 1.0 1.0 1.0 Particle Size, μm N.m.N.m. 0.5 6.5 6.5 6.5 6.5 Monosaccharide, Base Monosaccharide(s) NoneNone None Glucose None None None Polysaccharide, Substitutent(s) NoneNone None —CH₂COOH, None None None or Derivative —NO₂ Thereof Degree ofSubstitution None None None ≦1.8 None None None Degree of PolymerizationNone None None ≦3,000 None None None Concentration, ppt None None None0.005 None None None Dissolved Compound of Phosphorus None None NoneNone 0.50 ppt of None None ATMPA Vinyl acetate Derivative Polymer NoneNone None None None 0.50 ppt of None CMPVA Other Polymer None None NoneNone None None See Note 1 Alkali Salt Chemical None MgSO₄.7H₂O None NoneNone None None Concentration, g/L None 0.5 None None None None None NewAbbreviations and Other Notes for Table 2 “CE” means “ComparativeExample”; “PL-ZN” means ”PREPALENE ® ZN Concentration”; “N.m.” means“Not measured”; “ATMPA” means “aminotrimethylenephosphonic acid”;“CMPVA” means “Carboxyl-modified poly(vinyl alcohol)” Note 1: ThisComparative Example composition contained 0.010 ppt of a polymer made bypolymerizing a mixture of monomers containing 20% by weight of ethylacrylate, 30% by weight of maleic acid, and 50% by weight of vinylsulfonic acid. General Note: All of the Comparison Example 1-7compositions were contacted with substrates at 20° C. for 30 seconds.

which purification by decantation was carried out 10 times. Theprecipitate afforded by filtration was then dried and analyzed by x-raydiffraction and was confirmed to be phosphophyllite, which has thechemical formula Zn₂Fe(PO₄)₂. 4H₂O, containing some tertiary ironphosphate. To each one kilogram (hereinafter usually abbreviated as“kg”) of this predominantly phosphophyllite powder was added 50 g of theproduct afforded by the preliminary dilution/dissolution of themonosaccharide, polysaccharide, or derivative thereof reported in Table1 to 10% by weight in water and isopropyl alcohol. This was followed bymilling for about one hour in a ball mill using zirconia balls with adiameter of 0.5 millimeter (hereinafter usually abbreviated as “mm”).After milling, tap water was added to adjust the phosphophylliteconcentration in the suspension to 1.0 g/L, and the suspension was thenused as the surface conditioning liquid composition. The averageparticle size of the microparticles in the suspension after adjustmentwas measured to be 0.5 μm, using a laser diffraction/scatteringinstrument for measuring particle size distribution (LA-920 fromKabushiki Kaisha Horiba Seisakusho).

EXAMPLE 2

Predominantly phosphophyllite powder was prepared in the same manner asin Example 1, and 100 g of this powder was added per 1.0 kg of theproduct afforded by the preliminary dilution/dissolution of themonosaccharide, polysaccharide, or derivative thereof reported in Table1 to 10% by weight in water and isopropyl alcohol. This was followed bymilling for about one hour in a ball mill using zirconia balls with adiameter of 0.5 mm. After milling, tap water was added to adjust thephosphophyllite concentration in the suspension to 1.0 g/L, and thesuspension was then used as the surface conditioning liquid composition.The average particle size of the microparticles in the suspension afteradjustment was measured at 0.5 μm using the same instrument as inexample 1.

EXAMPLE 3

Predominantly phosphophyllite powder was prepared in the same manner asin Example 1, and to each 1.0 kg of this powder was added 100 g of theproduct afforded by the preliminary dilution/dissolution of themonosaccharide, polysaccharide, or derivative thereof reported in Table1 to 10% by weight in water. This was followed by milling for about onehour in a ball mill using zirconia balls with a diameter of 0.5 mm.After milling, tap water was added to adjust the phosphophylliteconcentration in the suspension to 1.0 g/L. The average particle size ofthe microparticles in the suspension after adjustment was measured at0.5 μm using the same instrument as in Example 1. 0.5 g/L of sodiumnitrite reagent (alkali salt) was then added and the resulting productwas used as the surface conditioning liquid composition.

EXAMPLE 4

Predominantly phosphophyllite powder was prepared in the same manner asin Example 1, and 50 g of this powder was added per 1.0 kg of theproduct afforded by the preliminary dilution/dissolution of themonosaccharide, polysaccharide, or derivative thereof reported in Table1 to 10% by weight in water. This was followed by milling for about onehour in a ball mill using zirconia balls with a diameter of 0.5 mm.After milling, tap water was added to adjust the phosphophylliteconcentration in the suspension to 1.0 g/L. The average particle size ofthe microparticles in the suspension after adjustment was measured at0.5 μm using the same instrument as in Example 1. 0.5 g/L of magnesiumsulfate heptahydrate reagent (alkali salt) was then added and theresulting product was used as the surface conditioning liquidcomposition.

EXAMPLE 5

Predominantly phosphophyllite powder was prepared in the same manner asin Example 1, and 50 g of this phosphophyllite was added per 1.0 kg ofthe product afforded by the preliminary dilution/dissolution of themonosaccharide, polysaccharide, or derivative thereof reported in Table1 to 10% by weight in water. This was followed by milling for about onehour in a ball mil using zirconia balls with a diameter of 0.5 mm. Aftermilling, tap water was added to adjust the phosphophyllite concentrationin the suspension to 10 g/L, and the suspension was then used as thesurface conditioning liquid composition. The average particle size ofthe microparticles in the suspension after adjustment was measured at0.5 μm using the same instrument as in Example 1.

EXAMPLE 6

Predominantly phosphophyllite powder was prepared in the same manner asin Example 1, and 1.0 kg of this powder was added per 1.0 kg of theproduct afforded by the preliminary dilution/dissolution of themonosaccharide, polysaccharide, or derivative thereof reported in Table1 to 10% by weight in water. This was followed by milling for about onehour in a ball mill using zirconia balls with a diameter of 0.5 mm.After milling, tap water was added to adjust the phosphophylliteconcentration in the suspension to 1.0 g/L, and the suspension was thenused as the surface conditioning liquid composition. The averageparticle size of the microparticles in the suspension after adjustmentwas measured at 0.5 μm using the same instrument as in Example 1.

EXAMPLE 7

1.0 kg of reagent grade Zn₃(PO₄)₂. 4H₂O was added per 1.0 kg of theproduct afforded by the preliminary dilution/dissolution of themonosaccharide, polysaccharide, or derivative thereof reported in Table1 to 10% by weight in water. This was followed by milling for about onehour in a ball mil using zirconia balls with a diameter of 0.5 mm. Aftermilling, tap water was added to adjust the Zn₃(PO₄)₂. 4H₂O concentrationin the suspension to 1.0 g/L, and the suspension was then used as thesurface conditioning liquid composition. The average particle size ofthe microparticles in the suspension after adjustment was measured as0.6 μm using the same instrument as in Example 1.

EXAMPLE 8

10 g of the product afforded by the preliminary dilution/dissolution ofthe monosaccharide, polysaccharide, or derivative thereof reported inTable 1 to 10% by weight in water was added per 1.0 kg of reagent gradeZn₃(PO₄)₂. 4H₂O. This was followed by milling for about one hour in aball mill using zirconia balls with a diameter of 10 mm. After milling,tap water was added to adjust the Zn₃(PO₄)₂. 4H₂O concentration in thesuspension to 1.0 g/L. The average particle size of the microparticlesin the suspension after adjustment was measured as 12 μm using the sameinstrument as in Example 1. 5 g/L of sodium metasilicate reagent (alkalisalt) was then added and the resulting product was used as the surfaceconditioning liquid composition.

EXAMPLE 9

A precipitate was produced by the addition of 200 mL of a 1.0 mol/Lsolution of zinc nitrate and then 200 mL of a 1.0 mol/L solution ofsodium monohydrogen phosphate to one liter of a 0.1 mol/L solution ofcalcium nitrate that had been heated to 50° C. Theprecipitate-containing aqueous solution was heated for one hour at 90°C. in order to ripen the precipitate particles, after which purificationby decantation was carried out 10 times. The precipitate afforded byfiltration was then dried and analyzed by x-ray diffraction and wasconfirmed to be scholzite, which has the chemical formulaZn₂Ca(PO₄)₂−2H₂O. To each 1.0 kg of this scholzite was added 10 g of theproduct afforded by the preliminary dilution/dissolution of themonosaccharide, polysaccharide, or derivative thereof reported in Table1 to 10% by weight in water. This was followed by milling for about onehour in a ball mill using zirconia balls with a diameter of 0.5 mm.After milling, tap water was added to adjust the scholzite concentrationin the suspension to 10 g/L. The average particle size of themicroparticles in the suspension after adjustment was measured at 0.4 μmusing the same instrument as in Example 1. 1.0 g/L of sodium carbonatereagent (alkali salt) was also added and the resulting product was usedas the surface conditioning liquid composition.

EXAMPLE 10

A precipitate was produced by the addition of 200 mL of a 1.0 mol/Lsolution of zinc nitrate and then 200 mL of a 1.0 mol/L solution ofsodium monohydrogen phosphate to 1.0 liter of a 0.1 mol/L solution ofcalcium nitrate that had been heated to 50° C. Theprecipitate-containing aqueous solution was heated for one hour at 90°C. in order to ripen the precipitate particles, after which purificationby decantation was carried out 10 times. The precipitate afforded byfiltration was then dried and analyzed by x-ray diffraction and wasconfirmed to be scholzite (Zn₂Ca(PO₄)₂−2H₂O). To each 1.0 kg of thisscholzite was added 10 g of the product afforded by the preliminarydilution/dissolution of the monosaccharide, polysaccharide, orderivative thereof reported in Table 1 to 10% by weight in water. Thiswas followed by milling for about one hour in a ball mill using zirconiaballs with a diameter of 0.5 mm. After milling, tap water was added toadjust the scholzite concentration in the suspension to 5 g/L. Theaverage particle size of the microparticles in the suspension afteradjustment was measured at 0.4 μm using the same instrument as inExample 1. 10 g/L of trisodium phosphate reagent (alkali salt) and 2 g/Lof a commercial polyoxyethylene nonylphenyl ether surfactant were alsoadded, and the resulting product was used as the surface conditioningliquid composition. The degreasing step was not run in this example;rather, a simultaneous cleaning and surface conditioning was rundirectly on the unaltered antirust oil-contaminated test specimen.

COMPARATIVE EXAMPLE 1

In this comparative example, surface conditioning was run usingPREPALENE® ZN aqueous solution (commercial product of Nihon ParkerizingCo., Ltd.), which is a prior-art surface conditioner. Surfaceconditioning was run using the standard conditions for use of thisproduct.

COMPARATIVE EXAMPLE 2

In this comparative example, surface conditioning was run using theliquid composition afforded by the addition of 0.5 g/L magnesium sulfateheptahydrate (alkali salt) as reported in Table 2 to the PREPALENE® ZNaqueous solution identified above as a prior-art surface conditioner.

COMPARATIVE EXAMPLE 3

A predominantly phosphophyllite powder was prepared in the same manneras for Example 1. This powder was suspended in water and then ground ina ball mill using. Zirconia balls with a diameter of 0.5 mm until theaverage particle size in the suspension reached 0.5 μm as measured usingthe same instrument as in Example 1. After milling, tap water was addedto adjust the phosphophyllite concentration in the suspension to 1.0g/L, and the suspension was then used as the surface conditioning liquidcomposition.

COMPARATIVE EXAMPLE 4

A predominantly phosphophyllite powder was prepared in the same manneras for Example 1. This powder was ground for about 2 minutes with amortar, then diluted with tap water and filtered across 5 μm paperfilter, and the filtrate was discarded. The precipitate was thereafterdried for one hour at 80° C. To each 1.0 kg of this dried powder wasadded 50 g of the product afforded by the preliminarydilution/dissolution of the monosaccharide, polysaccharide, orderivative thereof reported in Table 1 to 10% by weight in water andisopropyl alcohol. The dried powder +polymeric monosaccharide,polysaccharide, or derivative thereof was then adjusted with tap waterto give a dried powder concentration of 1.0 g/L, and the resultingsuspension was used as the surface conditioning liquid composition. Theaverage particle size of the microparticles in the suspension afteradjustment was measured at 6.5 μm using the same instrument as inExample 1.

Table 3 reports the coating properties of conversion coatings obtainedby zinc phosphating treatments that employed surface conditioning bathsprepared in the working

TABLE 3 Measurement or Test and Unit Measurement or Test Result forExample Number: Time of Use if Applicable Substrate 1 2 3 4 5 6 7 8 9 10Directly after CA SPC ++ ++ ++ ++ ++ ++ ++ ++ ++ ++ preparation EG ++ ++++ ++ ++ ++ ++ ++ ++ ++ GA ++ ++ ++ ++ ++ ++ ++ ++ ++ ++ Al ++ ++ ++ ++++ ++ ++ ++ ++ ++ Zn-Ni ++ ++ ++ ++ ++ ++ ++ ++ ++ ++ MP ++ ++ ++ ++ ++++ ++ ++ ++ ++ CW, g/m² SPC 1.6 1.7 1.5 1.6 1.6 1.6 1.5 1.7 1.4 1.5 EG1.7 1.9 1.8 1.7 1.8 1.7 1.6 1.7 1.6 1.7 GA 2.2 2.4 2.4 2.3 2.6 2.7 2.52.4 2.6 2.4 Al 1.9 1.8 1.8 1.9 1.6 1.7 1.7 1.6 1.7 1.7 Zn-Ni 1.6 1.7 1.61.5 1.6 1.6 1.7 1.8 1.6 1.8 MP 2.5 2.6 2.5 2.7 2.6 2.7 2.5 2.6 2.6 2.7CS, μm SPC 1-2 1-2 1-2 1-2 1-2 1-2 1-2 1-2 ≦1 1-2 EG 1-2 1-2 1-2 1-2 1-21-2 1-2 1-2 1-2 1-2 GA 2-3 2-3 2-3 2-3 2-3 2-3 2-3 2-3 1-2 2-3 Al 1-21-2 1-2 1-2 1-2 1-2 1-2 1-2 1-2 1-2 Zn-Ni 1-2 1-2 1-2 1-2 1-2 1-2 1-21-2 1-2 1-2 MP 2-3 2-3 2-3 2-3 2-3 2-3 2-3 2-3 2-3 2-3 PPR SPC 95 96 9796 93 92 92 91 90 91 After standing CA SPC ++ ++ ++ ++ ++ ++ ++ ++ ++ ++for 10 days CW, g/m² SPC 1.5 1.6 1.6 1.6 1.6 1.5 1.5 1.7 1.5 1.5 CS, μmSPC 1-2 1-2 1-2 1-2 1-2 1-2 1-2 1-2 1-2 1-2 PPR SPC 96 96 95 97 95 92 9191 92 90 New Abbreviation in Table 3 “PPR” means ”100 × ‘P ratio’”

examples, and Table 4 reports the coating properties of conversioncoatings obtained by zinc phosphating treatments that employed surfaceconditioning baths prepared in the comparative examples.

The results in Tables 3 and 4 confirm that the timewise stability, whichhas been a problem for prior-art technologies, is substantially improvedin the case of the surface conditioning baths according to the presentinvention. The effect of the monosaccharide, polysaccharide, orderivative thereof on the surface conditioning activity is alsounder-scored from the results in Comparative Example 3, Example 1, andExample 2. In addition, Comparative Example 3, although also inferior toExample 1 immediately after preparation of the surface conditioningliquid composition, nevertheless at that point had a surfaceconditioning activity that was at least equal to that of ComparativeExample 1 (prior art).

However, in the case of Comparative Example 3, milling of the divalentor trivalent metal phosphate was quite difficult and a sediment of thedivalent or trivalent metal

TABLE 4 Measurement or Measurement or Test Result for Test and UnitComparative Example Number: Time of Use if Applicable Substrate 1 2 3 45 6 7 Directly after CA SPC ++ x + xx xx xx xx preparation EG ++ Δ ++ ΔΔ Δ Δ GA ++ + ++ Δ Δ Δ Δ Al x xx Δ xx xx xx xx Zn-Ni ++ ++ ++ Δ Δ Δ ΔMP + x ++ + + + + CW, g/m² SPC 2.4 3.8 2.0 N.m. N.m. N.m. N.m. EG 2.73.2 2.8 3.8 3.9 3.8 4.0 GA 3.1 3.5 3.3 4.4 4.2 4.3 4.7 Al 0.9 N.m. 1.3N.m. N.m. N.m. N.m. Zn-Ni 2.5 3.3 2.7 3.6 3.4 3.5 3.5 MP 3.6 1.8 2.8 3.33.4 3.5 3.3 CS, μm SPC 3-4 >10 2-3 N.m. N.m. N.m. N.m. EG 3-4 7-82-3 >10 >10 >10 >10 GA 5-6  7-10 3-4 >10 >10 >10 >10 Al 4-5 N.m. 2-3N.m. N.m. N.m. N.m. Zn-Ni 3-4 6-9 2-3 >10 >10 >10 >10 MP 5-6  8-10 3-45-6 5-6 5-6 5-6 PPR SPC 93 N.m. 95 N.m. N.m. N.m. N.m. After standing CASPC x xx Δ xx xx xx xx for 10 days CW, g/m² SPC 3.3 N.m. 2.8 N.m. N.m.N.m. N.m. CS, μm SPC 7-8 N.m. 3-4 N.m. N.m. N.m. N.m. PPR SPC N.m. N.m.92 N.m. N.m. N.m. N.m.

phosphate was produced in the treatment liquid composition after theelapse of 10 days. These problems with Comparative Example 3 were due tothe absence of any accelerant component as described above for theinvention and resulting re-aggregation of the divalant or trivalentmetal phosphate. Furthermore, although this series of examples exploredvariations in the type of monosaccharide, polysaccharide, or derivativethereof, in the type of alkali salt, and in the treatment temperature,no changes in activity were thereby noted and dense, ricrofine crystalswere produced that were equal to or superior to the crystals produced bythe prior-art technologies.

Table 5 reports the compositions of surface conditioning liquidcompositions used in examples of the present invention in which a watersoluble compound of phosphorus was the accelerant component. Table 5 andComparative Example 5 in Table 2 report the particular selection fromorthophosphoric acid, condensed phosphoric acids, and organophosphonicacid compounds. The phosphorus compounds used in the examples in Table 5and in Comparative Example 5 were selected from reagents and commercialproducts (from, for example, Monsanto Japan Ltd.) in order to explorestructural

TABLE 5 Component Type and Details Example 11 Example 12 Example 13Example 14 Example 15 Phosphate Salt Chemical PHOS PHOS PHOS ZPTH SCHOConcentration, g/L 5.0 1.0 1.0 5.0 10 Particle Size, μm 0.5 0.5 1.7 0.60.5 Dissolved Chemical TPPA HMPA ATMPA HEDP EDTMPA Compound ofConcentration, g/L 0.0010 0.10 0.50 0.050 1.0 Phosphorus Alkali SaltChemical MgSO₄.7H₂O Na₂.SiO₂.5H₂O None NaCO₃ Na₃PO₄.12H₂O Concentration,g/L 0.50 1.0 None 5.0 10 Surfactant Chemical None None None None(EO)₁₁NPE Concentration, g/L None None None None 2.0 TreatmentTemperature, ° C. 20 20 20 20 40 Conditions Time, Seconds 30 30 30 30120 New Abbreviations for Table 5 “TPPA” means “tripolyphosphoric acid”;“HMPA” means “hexameta phosphoric acid”; “HEDP” means“1-hydroxy-ethylidene-1,1-diphosphonic acid”; “EDTMPA” means“ethylenediamine tetramethylene phosphonic acid”.

variations. While the effects of the present invention do not imposelimitations on the pH of the surface conditioning liquid composition, inthe case of very low pH phosphorus compounds the pH of the phosphoruscompound was preliminarily adjusted to neutrality using sodium hydroxidein order to prevent dissolution of the divalent or trivalent metalphosphate. Timewise testing in this series was carried out by using thesurface conditioning liquid composition after it had been held for 10days at room temperature after its preparation. Further details for theindividual examples are given below.

EXAMPLE 11

Predominantly phosphophyllite powder was prepared in the same manner asfor Example 1. To each 1.0 kg of this powder was added 2 g of theproduct afforded by the preliminary dilution/dissolution of thephosphorus compound reported in Table 5 to 10% by weight in water. Thiswas followed by milling for about 1 hour in a ball mill using zirconiaballs with a diameter of 0.5 mm. After milling, tap water was added toadjust the phosphophyllite concentration in the suspension to 5 g/L. Theaverage particle size of the microparticles in the suspension afteradjustment was measured as 0.5 μm using the same instrument as inExample 1. 0.5 g/L of magnesium sulfate heptahydrate reagent (alkalisalt) was also added and the resulting product was used as the surfaceconditioning liquid composition.

EXAMPLE 12

Predominantly phosphophyllite powder was prepared in the same manner asfor Example 1. To each 1.0 kg of this powder was added 1.0 kg of theproduct afforded by the preliminary dilution/dissolution of thephosphorus compound reported in Table 5 to 10% by weight in water. Thiswas followed by milling for about 1 hour in a ball mill using zirconiaballs with a diameter of 0.5 mm. After milling, tap water was added toadjust the phosphophyllite concentration in the suspension to 1.0 g/L.The average particle size of the microparticles in the suspension afteradjustment was measured as 0.5 μm using the same instrument as inExample 1. 1.0 g/L of sodium metasilicate reagent (alkali salt) was alsoadded and the resulting product was used as the surface conditioningliquid composition.

EXAMPLE 13

Predominantly phosphophyllite powder was prepared in the same manner asfor is Example 1. 200 g of this powder was added per 1.0 kg of theproduct afforded by the preliminary dilution/dissolution of thephosphorus compound reported in Table 5 to 10% by weight in water. Thiswas followed by milling for about 1 hour in a ball mill using zirconiaballs with a diameter of 10 mm. After milling, tap water was added toadjust the phosphophyllite concentration in the suspension to 1.0 g/L,and the suspension was then used as the surface conditioning liquidcomposition. The average particle size of the microparticles in thesuspension after adjustment was measured as 1.7 μm using the sameinstrument as in Example 1.

EXAMPLE 14

100 g of the product afforded by the preliminary dilution/dissolution ofthe phosphorus compound reported in Table 5 to 10% by weight in waterwas added per 1.0 kg of reagent grade Zn₃(PO₄)₂. 4H₂O. This was followedby milling for about 1 hour in a ball mill using zirconia balls with adiameter of 0.5 mm. After milling, tap water was added to adjust theZn₃(PO₄)₂. 4H₂O concentration in the suspension to 5 g/L. The averageparticle size of the microparticles in the suspension after adjustmentwas measured as 0.6 μm using the same instrument as in Example 1. 5 g/Lof sodium carbonate reagent (alkali salt) was also added and theresulting product was used as the surface conditioning liquidcomposition.

EXAMPLE 15

Scholzite powder was prepared in the same manner as for Example 9. 1.0kg of this scholzite was added per 1.0 kg of the product afforded by thepreliminary dilution/dissolution of the phosphorus compound reported inTable 5 to 10% by weight in water. This was followed by milling forabout 1 hour in a ball mill using zirconia balls with a diameter of 0.5mm. After milling, tap water was added to adjust the scholziteconcentration in the suspension to 10 g/L. The average particle size ofthe microparticles in the suspension after adjustment was measured at0.5 μm using the same instrument as in Example 1. 10 g/L of trisodiumphosphate reagent (alkali salt) and 2 g/L of a commercialpolyoxyethylene nonylphenyl ether (surfactant) were also added and theresulting product was used as the surface conditioning liquidcomposition. The degreasing step was not run in this example; rather, asimultaneous cleaning and surface conditioning was run directly on theunaltered antirust oil-contaminated test specimen.

COMPARATIVE EXAMPLE 5

Predominantly phosphophyllite powder was prepared in the same manner asfor Example 1. This powder was ground for about 2 minutes with a mortar,then diluted with tap water and filtered through 5 μm paper filter, andthe filtrate was discarded. The powder was thereafter dried for 1 hourat 80° C. 100 g of this dried powder was added per 500 g of the productafforded by the preliminary dilution to 10% by weight in water of the isphosphorus compound reported for Comparative Example 5 in Table 2. Thesurface conditioning liquid composition was prepared by diluting withtap water to give a dried powder concentration of 1.0 g/L. The averageparticle size of the microparticles in the suspension after adjustmentwas measured at 6.5 μm using the same instrument as in Example 1.

Table 6 reports the coating properties of conversion coatings obtainedby zinc phosphating treatments that employed surface conditioning bathsprepared in the working examples 11-15. Comparative Example 5 in Table 4reports the coating properties of the conversion coating obtained by azinc phosphating treatment that employed the surface conditioning liquidcomposition prepared in Comparative Example 5.

The results in Tables 6 and 4 confirm that the timewise stability, whichhas been a problem for prior-art technologies, is substantially improvedin the case of the surface conditioning baths according to the presentinvention. The effect of the orthophosphoric acid, condensed phosphoricacid, or organophosphonic acid compound on the surface conditioningactivity is also underscored from the results in Comparative Example 3and Example 13.

In addition, Comparative Example 3, although also inferior to Example 11immediately after preparation of the surface conditioning liquidcomposition, nevertheless at that point had a surface conditioningactivity that was at least equal to that of Comparative Example 1 (priorart). However, in the case of Comparative Example 3, milling of thedivalant or trivalent metal phosphate was quite difficult and a sedimentof the divalent or trivalent metal phosphate was produced in thetreatment liquid composition after the elapse of 10 days. These problemswith Comparative Example 3 were due to the absence of

TABLE 6 Measurement or Test Result for Measurement or Test ExampleNumber: Time of Use and Unit if Applicable Substrate 11 12 13 14 15Directly after CA SPC ++ ++ ++ ++ ++ preparation EG ++ ++ ++ ++ ++ GA ++++ ++ ++ ++ Al ++ ++ ++ ++ ++ Zn-Ni ++ ++ ++ ++ ++ MP ++ ++ ++ ++ ++ CW,g/m² SPC 1.7 1.6 1.8 1.7 1.7 EG 1.8 1.8 1.9 1.8 1.7 GA 2.3 2.2 2.3 2.22.3 Al 1.7 1.7 1.7 1.6 1.7 Zn-Ni 1.6 1.6 1.7 1.6 1.7 MP 2.5 2.4 2.6 2.52.7 CS, μm SPC 1-2 1-2 1-2 1-2 1-2 EG 1-2 1-2 1-2 1-2 1-2 GA 2-3 2-3 2-32-3 2-3 Al 1-2 1-2 1-2 1-2 1-2 Zn-Ni 1-2 1-2 1-2 1-2 1-2 MP 2-3 2-3 2-32-3 2-3 PPR SPC 97 97 93 92 93 After standing CA SPC ++ ++ ++ ++ ++ for10 days CW, g/m² SPC 1.7 1.7 1.7 1.7 1.6 CS, μm SPC 1-2 1-2 1-2 1-2 1-2PPR SPC 97 96 95 93 93

any accelerant component as described above for this invention and theresulting re-aggregation of the divalent or trivalent metal phosphate.Furthermore, although this series of examples explored variations in theorthophosphoric acid, condensed phosphoric acid, and organophosphonicacid compound and in the type of alkali salt and the treatmenttemperature, no changes in activity were thereby noted and dense,micro-fine crystals were produced that were equal to or superior to thecrystals produced by the prior-art technologies.

In addition, Comparative Example 3, although also inferior to Example 11immediately after preparation of the surface conditioning liquidcomposition, nevertheless at that point had a surface conditioningactivity that was at least equal to that of Comparative Example 1 (priorart). However, in the case of Comparative Example 3, milling of thedivalant or trivalent metal phosphate was quite difficult and a sedimentof the divalent or trivalent metal phosphate was produced in thetreatment liquid composition after the elapse of 10 days. These problemswith Comparative Example 3 were due to the absence of is theorthophosphoric acid, condensed phosphoric acid, or organophosphonicacid compound and the resulting re-aggregation of the divalent ortrivalent metal phosphate. Furthermore, although this series of examplesexplored variations in the orthophosphoric acid, condensed phosphoricacid, and organophosphonic acid compound and in the type of alkali saltand the treatment temperature, no changes in activity were thereby notedand dense, microfine crystals were produced that were equal to orsuperior to the crystals produced by the prior-art technologies.

Table 7 reports the compositions of surface conditioning baths used inexamples according to the present invention when the accelerantcomponent is a water-soluble polymer. Table 7 and Comparative Example 6in Table 2 use the “Vinyl Acetate/Derivative Polymer” heading to reportthe particular selection from water-soluble polymer compounds comprisingvinyl acetate polymers and derivatives thereof and copolymers of vinylacetate and vinyl acetate-copolymerizable monomer. The vinyl acetatepolymers and derivatives thereof reported in the tables were prepared bythe polymerization of vinyl acetate using a peroxide initiator followedby introduction of the functional group reported in the particularexample by hydrolysis, acetalation, etc. The copolymers of vinyl acetateand vinyl acetate-copolymerizable monomer were synthesized bycopolymerizing vinyl acetate and the particular monomer. Timewisetesting in this series was carried out by using the surface conditioningliquid composition after it had been held for 10 days at roomtemperature after its preparation. Further details of individualexamples are given below.

EXAMPLE 16

Predominantly phosphophyllite powder was prepared in the same manner asfor Example 1. To each 1.0 kg of this powder was added 2 g of theproduct afforded by the preliminary dilution/dissolution of thewater-soluble polymer compound reported in Table 7 to 10% by weight inwater. This was followed by milling for about 1 hour in a ball millusing zirconia balls with a diameter of 0.5 mm. After milling, tap waterwas added to adjust the phosphophyllite concentration in the suspensionto 5 g/L. The average particle size of the microparticles in thesuspension after adjustment was measured at 0.5 μm using the sameinstrument as in Example 1. 0.5 g/L of sodium metasilicate reagent(alkali salt) was also added and the resulting product was used as thesurface conditioning liquid composition.

EXAMPLE 17

Predominantly phosphophyllite powder was prepared in the same manner asfor Example 1. 100 g of this powder was added per 500 g of the productafforded by the preliminary dilution/dissolution of the water-solublepolymer compound reported in Table 7 to 10% by weight in water. This wasfollowed by milling for about 1 hour in a ball mill using zirconia ballswith a diameter of 0.5 mm. After milling, tap water was added to

TABLE 7 Component Type and Details Example 16 Example 17 Example 18Example 19 Example 20 Phosphate Salt Chemical PHOS PHOS ZPTH SCHO SCHOConcentration, g/L 5.0 1.0 1.0 5.0 30 Particle Size, μm 0.5 0.5 0.5 1.60.3 Vinyl Acetate/Derivative Polymer 0.0010 ppt of 0.50 ppt of 2.0 pptof See Note 1 See Note 2 PVAc CMPVA SAMPVA Alkali Salt ChemicalNa₂SiO₃.5H₂O None MgSO₄.7H₂O NaCO₃ Na₃PO₄.12H₂O Concentration, g/L 0.50None 0.50 5.0 10 Surfactant Chemical None None None None (EO)₁₁NPEConcentration, g/L None None None None 2.0 Treatment Temperature, ° C.20 20 20 20 40 Conditions Time, Seconds 30 30 30 30 120 NewAbbreviations and Other Notes for Table 7 “PVAc” means “poly(vinylacetate)”; “SAMPVA” means “sulfonic acid modified poly(vinyl alcohol)”.Note 1: This Example Composition contained 1.0 ppt of a copolymer of 80%maleic acid and 20% vinyl acetate monomers. Note 2: This ExampleComposition contained 0.030 ppt of a copolymer of 70% crotonic acid and30% vinyl acetate monomers.

adjust the phosphophyllite concentration in the suspension to 1.0 g/L,and the suspension was then used as the surface conditioning liquidcomposition. The average particle size of the microparticles in thesuspension after adjustment was measured at 0.5 μm using the sameInstrument as in Example 1.

EXAMPLE 18

50 g of reagent grade Zn₃(PO₄)₂. 4H₂O was added per 1.0 kg of theproduct afforded by the preliminary dilution/dissolution of thewater-soluble polymer compound reported in Table 7 to 10% by weight inwater. This was followed by milling for about 1 hour in a ball millusing zirconia balls with a diameter of 0.5 mm. After milling, tap waterwas added to adjust the Zn₃(PO₄)₂. 4H₂O concentration in the suspensionto 1.0 g/L. The average particle size of the microparticles in thesuspension after adjustment was measured at 0.5 μm using the sameinstrument as in Example 1. 0.5 g/L magnesium sulfate heptahydratereagent (alkali salt) was also added and the resulting product was usedas the surface conditioning liquid composition.

EXAMPLE 19

Scholzite powder was prepared in the same manner as in Example 9. 500 gof this scholzite was added per 1.0 kg of the product afforded by thepreliminary dilution/dissolution of the water-soluble polymer compoundreported in Table 7 to 10% by weight in water. This was followed bymilling for about 1 hour in a ball mill using zirconia balls with adiameter of 10 mm. After milling, tap water was added to adjust thescholzite concentration in the suspension to 5 g/L. The average particlesize of the microparticles in the suspension after adjustment wasmeasured at 1.6 μm using the same instrument as in Example 1. 5 g/L ofsodium carbonate reagent (alkali salt) was also added and the resultingproduct was used as the surface conditioning liquid composition.

EXAMPLE 20

Scholzite powder was prepared in the same manner as for Example 9. Toeach 1.0 kg of this scholzite was added 10 g of the product afforded bythe preliminary dilution/dissolution of the water-soluble polymercompound reported in Table 7 to 10% by weight in water. This wasfollowed by milling for about 1 hour in a ball mill using zirconia ballswith a diameter of 0.5 mm. After milling, tap water was added to adjustthe scholzite concentration in the suspension to 30 g/L. The averageparticle size of the micro-particles in the suspension after adjustmentwas measured at 0.3 μm using the same instrument as in Example 1. 10 g/Lof tertiary sodium phosphate reagent (alkali salt) and 2 g/L of acommercial polyoxyethylene nonylphenyl ether (surfactant were also addedand the resulting product was used as the surface conditioning liquidcomposition. The degreasing step was not run in this example; rather, asimultaneous cleaning and surface conditioning was run directly on theunaltered antirust oil-contaminated test specimen.

COMPARATIVE EXAMPLE 6

A predominantly phosphophyllite powder was prepared in the same manneras in Example 1. This powder was ground for about 2 minutes with amortar, then diluted with tap water and filtered through 5 μm paperfilter, and the filtrate was discarded. The powder was thereafter driedfor 1 hour at 80° C. 100 g of this dried powder was added per 500 g ofthe product afforded by the preliminary dilution/dissolution to 10% byweight in water of the water-soluble polymer compound reported inComparative Example 6 of Table 2. The surface conditioning liquidcomposition was obtained by adjustment with tap water to give a driedpowder concentration of 1.0 g/L. The average particle size of themicroparticles in the suspension after adjustment was measured at 6.5 μmusing the same instrument as in Example 1.

Table 8 reports the coating properties of conversion coatings obtainedby zinc phosphating treatments that employed surface conditioning bathsprepared in working Examples 16-20. Comparative Example 6 in Table 4reports the coating properties of the conversion coating obtained by azinc phosphating treatment that employed the surface conditioning liquidcomposition prepared in Comparative Example 6.

TABLE 8 Measurement or Test Result for Measurement or Test ExampleNumber: Time of Use and Unit if Applicable Substrate 16 17 18 19 20Directly after CA SPC ++ ++ ++ ++ ++ preparation EG ++ ++ ++ ++ ++ GA ++++ ++ ++ ++ Al ++ ++ ++ ++ ++ Zn-Ni ++ ++ ++ ++ ++ MP ++ ++ ++ ++ ++ CW,g/m² SPC 1.7 1.6 1.7 1.8 1.4 EG 1.8 1.7 1.8 1.9 1.6 GA 2.4 2.2 2.3 2.42.2 Al 1.7 1.7 1.8 1.9 1.7 Zn-Ni 1.6 1.5 1.6 1.7 1.5 MP 2.7 2.6 2.8 2.62.5 CS, μm SPC 1-2 1-2 1-2 1-2 ≦1 EG 1-2 1-2 1-2 1-2 1-2 GA 2-3 2-3 2-32-3 2-3 Al 1-2 1-2 1-2 1-2 1-2 Zn-Ni 1-2 1-2 1-2 1-2 1-2 MP 2-3 2-3 2-32-3 2-3 PPR SPC 97 97 93 92 93 After standing CA SPC ++ ++ ++ ++ ++ for10 days CW, g/m² SPC 1.6 1.7 1.7 1.7 1.5 CS, μm SPC 1-2 1-2 1-2 1-2 1-2PPR SPC 96 97 92 92 93

The results in Tables 8 and 4 confirm that the timewise stability, whichhas been a problem for prior-art technologies, is substantially improvedin the case of the surface conditioning baths according to the presentinvention. The results in Comparative Example 3 and Example 17 alsounderscore the effect on the surface conditioning activity of thewater-soluble polymer compounds comprising vinyl acetate polymers andderivatives thereof and copolymers of vinyl acetate and vinylacetate-copolymerizable monomer. In addition, Comparative Example 3,although also inferior to Example 16 immediately after preparation ofthe surface conditioning liquid composition, nevertheless at that pointhad a surface conditioning activity that was at least equal to that ofComparative Example 1 (prior art).

However, in the case of Comparative Example 3, milling of the divalentor trivalent metal phosphate was quite difficult and a sediment of thedivalent or trivalent metal phosphate was produced in the treatmentliquid composition after the elapse of 10 days. These problems withComparative Example 3 were due to the absence of any accelerantcomponent as described above for this invention and the resultingre-aggregation of the divalent or trivalent metal phosphate.Furthermore, although this series of examples explored variations in thetype of water-soluble polymer compound comprising vinyl acetate polymersand derivatives thereof and copolymers of vinyl acetate and vinylacetate-copolymerizable monomer, in the type of alkali salt, and in thetreatment temperature, no changes in activity were thereby noted anddense, microfine crystals were produced that were equal to or superiorto the crystals produced by the prior-art technologies.

Table 9 reports the compositions of surface conditioning baths used inexamples according to the present invention when the accelerantcomponent was a polymer that included at least one of residues ofmonomers that conform to general formula (i) as given above or otherα,β-unsaturated carboxylic acid monomer residues. Polymer or copolymerwas prepared by polymerizing the monomer(s) reported in Table 9 andComparative Example 7 in Table 2 using ammonium persulfate as catalyst.Poorly water-soluble monomer was polymerized after emulsification usinga commercial surfactant. While the effects of the present invention donot impose narrow limitations on the pH of the surface conditioningliquid composition, in the case of very low pH polymer or copolymer thepH of the polymer or copolymer was preliminarily adjusted to neutralityusing sodium hydroxide in order to prevent dissolution of the divalentor trivalent metal phosphate. Timewise testing in this series wascarried out by using the surface conditioning liquid composition afterit had been held for 10 days at room temperature after its preparation.Additional details for particular examples are given below.

EXAMPLE 21

Predominantly phosphophyllite powder was prepared in the same manner asfor Example 1. To each 1.0 kg of this powder was added 1.0 g of theproduct afforded by microparticles in the suspension after adjustmentwas measured at 0.5 μm using the same instrument as in Example 1.

EXAMPLE 23

Predominantly phosphophyllite powder was prepared in the same manner asfor Example 1. 25 g of this powder was added per 1.0 kg of the productafforded by the preliminary dilution/dissolution of the polymer orcopolymer reported in Table 9 to 10% by 3o weight in water. This wasfollowed by milling for about 1 hour in a ball mill using zirconia ballswith a diameter of 0.5 mm. After milling, tap water was added to adjustthe phosphophyllite concentration in the suspension to 0.5 g/L. Theaverage particle size of the microparticles in the suspension afteradjustment was measured at 0.5 μm using the same instrument as inExample 1. 0.50 g/L of magnesium sulfate heptahydrate reagent (alkalisalt) was also added and the resulting product was used as the surfaceconditioning liquid composition.

TABLE 9 Characteristics for Example Numbers: Component Type and Details21 22 23 24 25 26 27 Phosphate Salt Chemical PHOS PHOS PHOS SCHO SCHOZPTH ZPTH Concentra- 10 1.0 0.50 10 5.0 1.0 1.0 tion, g/L Particle Size,0.5 0.5 0.5 0.6 0.6 1.2 0.5 μm Polymer First Chemical 2-Hydroxy- MaleicAcrylic 3-Hydroxypropyl Ethyl Acrylic Meth- Characteristics Monomerethyl acrylate acid acid methacrylic acid methacrylate acid acrylic acid% by Weight 100 80 100 20 20 70 50 of Monomer Second Chemical None VinylNone Maleic acid Maleic acid Maleic acid Styrene- Monomer acetatesulfonic acid % by Weight None 20 None 80 30 30 50 of Monomer ThirdChemical None None None None Vinyl sulfonic None None Monomer acid % byWeight None None None None 50 None None of Monomer PolymerConcentration, 0.001 0.50 2.0 1.5 0.010 0.10 0.005 ppt Alkali SaltChemical NaNO₂ None MgSO₄.7H₂O Na₂CO₃ Na₃PO₄.12H₂O Na₂SiO₃.5H₂O NoneConcentra- 0.5 None 0.5 0.5 10 5 None tion, g/L Surfactant Chemical NoneNone None None None (EO)₁₁NPE None Concentra- None None None None None2.0 None tion, g/L Treatment Conditions ° C. 20 20 20 20 20 40 20Seconds 30 30 30 30 30 120 30

EXAMPLE 24

A scholzite powder was prepared in the same manner as for Example 9. Toeach 1.0 kg of this scholzite was added 1.5 g of the product afforded bythe preliminary dilution/dissolution of the polymer or copolymerreported in Table 9 to 10% by weight in water. This was followed bymilling for about 1 hour in a ball mill using zirconia balls with adiameter of 0.5 mm. After milling, tap water was added to adjust thescholzite concentration in the suspension to 10 g/L. The averageparticle size of the microparticles in the suspension after adjustmentwas measured at 0.6 μm using the same instrument as in Example 1. 1.0g/L of sodium carbonate reagent (alkali salt) was also added and theresulting product was used as the surface conditioning liquidcomposition.

EXAMPLE 25

A scholzite powder was prepared in the same manner as for Example 9. Toeach 1.0 kg of this scholzite was added 20 g of the product afforded bythe preliminary dilution/dissolution of the polymer or copolymerreported in Table 9 to 10% by weight in water. This was followed bymilling for about 1 hour in a ball mill using zirconia balls with adiameter of 0.5 mm. After milling, tap water was added to adjust thescholzite concentration in the suspension to 5 g/L The average particlesize of the microparticles in the suspension after adjustment wasmeasured at 0.6 μm using the same instrument as in Example 1. 10 g/L oftertiary sodium phosphate reagent (alkali salt) was also added and Isthe resulting product was used as the surface conditioning liquidcomposition.

EXAMPLE 26

1.0 kg of reagent grade Zn₃(PO₄)₂. 4H₂O was added per 1.0 kg of theproduct afforded by the preliminary dilution/dissolution of the polymeror copolymer reported in Table 9 to 10% by weight in water. This wasfollowed by milling for about 1 hour in a ball mill using zirconia ballswith a diameter of 10 mm. After milling, tap water was added to adjustthe Zn₃(PO₄)₂. 4H₂O concentration in the suspension to 1.0 g/L. Theaverage particle size of the microparticles in the suspension afteradjustment was measured at 1.2 μm using the same instrument as inExample 1.5 g/L of sodium metasilicate reagent (alkali salt) and 2 g/Lof a commercial polyoxyethylene nonylphenyl ether (surfactant) were alsoadded and the resulting product was used as the surface conditioningliquid composition. The degreasing step was not run in this example;rather, a simultaneous cleaning and surface conditioning was rundirectly on the unaltered antirust oil-contaminated test specimen.

EXAMPLE 27

To each 1.0 kg of reagent grade Zn₃(PO₄)₂. 4H₂O was added 50 g of theproduct afforded by the preliminary dilution/dissolution of the polymeror copolymer reported in Table 9 to 10% by weight in water. This wasfollowed by milling for about 1 hour in a ball mill using zirconia ballswith a diameter of 0.5 mm. After milling, tap water was added to adjustthe Zn₃(PO₄)₂. 4H₂O concentration in the suspension to 1.0 g/L and thissuspension was used as the surface conditioning liquid composition. Theaverage particle size of the microparticles in the suspension afteradjustment was measured at 0.5 μm using the same instrument as inExample 1.

COMPARATIVE EXAMPLE 7

Predominantly phosphophyllite powder was prepared in the same manner asfor Example 1. This powder was ground for about 2 minutes with a mortar,then diluted with tap water and filtered through 5 μm paper filter, andthe filtrate was discarded. The powder was thereafter dried for 1 hourat 80° C. To each 1.0 kg of this dried powder was added 100 g of theproduct afforded by the preliminary dilution/dissolution to 10% byweight in water of the polymer or copolymer reported in ComparativeExample 7 of Table 2. The mixture of dried powder +polymer or copolymerwas then adjusted with tap water to give a dried powder concentration of1.0 g/L, and the resulting suspension was used la as the surfaceconditioning liquid composition. The average particle size of themicroparticles in the suspension after adjustment was measured at 6.5 μmusing the same instrument as in Example 1.

Table 10 reports the coating properties of conversion coatings obtainedby zinc phosphating treatments that employed surface conditioning bathsprepared in working examples 21-27. Comparative Example 7 in Table 4reports the coating properties of the conversion coating obtained by thezinc phosphating treatment that employed the surface conditioning liquidcomposition prepared in Comparative Example 7.

The results in Tables 10 and 4 confirm that the timewise stability,which has been a problem for prior-art technologies, is substantiallyimproved in the case of the surface conditioning baths according to thepresent invention. The effect of the polymer or copolymer on the surfaceconditioning activity is also underscored from the results inComparative Example 3, Example 22, and Example 27.

In addition, Comparative Example 3, although also inferior to Example 21immediately after preparation of the surface conditioning liquidcomposition, nevertheless at that point had a surface conditioningactivity that was at least equal to that of Comparative Example 1 (priorart). However, in the case of Comparative Example 3, milling of thedivalent or trivalent metal phosphate was quite difficult and a sedimentof the divalent or trivalent metal phosphate was produced in thetreatment liquid composition after the elapse of 10 days. These problemswith Comparative Example 3 were due to the absence of any accelerantcomponent as defined above for this invention Furthermore, although thisseries of examples explored variations in the type of polymer orcopolymer, in the type of alkali salt, and in the treatment temperature,no changes in activity were thereby noted and dense, microfine crystalswere produced that were equal to or superior to the crystals produced bythe prior-art technologies.

TABLE 10 Measurement or Measurement or Test Result for Test and UnitExample Number: Time of Use if Applicable Substrate 21 22 23 24 25 26 27Directly after CA SPC ++ ++ ++ ++ ++ ++ ++ preparation EG ++ ++ ++ ++ ++++ ++ GA ++ ++ ++ ++ ++ ++ ++ Al ++ ++ ++ ++ ++ ++ ++ Zn-Ni ++ ++ ++ ++++ ++ ++ MP ++ ++ ++ ++ ++ ++ ++ CW, g/m² SPC 1.4 1.7 1.7 1.5 1.7 1.71.6 EG 1.6 1.8 1.8 1.7 1.9 1.9 1.7 GA 2.2 2.3 2.3 2.3 2.4 2.4 2.5 Al 1.71.8 1.8 1.9 1.8 1.7 1.9 Zn-Ni 1.5 1.7 1.6 1.5 1.7 1.6 1.6 MP 2.5 2.5 2.42.6 2.5 2.7 2.5 CS, μm SPC ≦1 1-2 1-2 ≦1 1-2 1-2 1-2 EG 1-2 1-2 1-2 1-21-2 1-2 1-2 GA 2-3 2-3 2-3 2-3 2-3 2-3 1-2 Al 1-2 1-2 1-2 1-2 1-2 1-21-2 Zn-Ni 1-2 1-2 1-2 1-2 1-2 1-2 1-2 MP 2-3 2-3 2-3 2-3 2-3 2-3 2-3 PPRSPC 97 96 97 92 91 93 90 After standing CA SPC ++ ++ ++ ++ ++ ++ ++ for10 days CW, g/m² SPC 1.5 1.7 1.6 1.6 1.6 1.8 1.5 CS, μm SPC 1-2 1-2 1-21-2 1-2 1-2 1-2 PPR SPC 96 97 96 92 93 91 94

BENEFITS OF THE INVENTION

The surface conditioning liquid composition according to the presentinvention as described hereinabove provides a substantial improvement intimewise stability, which has been a problem with the prior-art titaniumcolloid technology, and also supports and enables an additionalmicrofine-sizing of the phosphate coating crystals that has beenunattainable by the prior-art. As a consequence, technology that usesthe surface conditioning liquid composition according to the presentinvention will be more economical than the prior-art technology and willstill be able to provide properties at least as good as the prior-arttechnology.

What is claimed is:
 1. A liquid composition for conditioning metalsurfaces prior to phosphate conversion coating treatment thereof, saidliquid composition containing an aqueous dispersion comprising thefollowing components: (A) a stably dispersed, undissolved solid powdercomponent that is constituted of phosphates that contain at least onedivalent or trivalent metal, the solid powder thereof having a particlesize of not more than 5 μm; and (B) an accelerant component selectedfrom the group consisting of the following subgroups: (1)monosaccharides, polysaccharides and derivatives thereof; (2)orthophosphoric acid, condensed phosphoric acids, and organophosphonicacid compounds; (3) water-soluble polymers that are homopolymers orcopolymers of vinyl acetate and derivatives of these homopolymers andcopolymers; and (4) copolymers and polymers as afforded by thepolymerization of, (a) at least one selection from: (i) monomers,exclusive of vinyl acetate, that conform to general chemical formula(1):

 where R¹=H or CH₃ and R²=H, C₁ to C₅ alkyl, or C₁ to C₅ hydroxyalkyl;and (ii) other α,β-unsaturated carboxylic acid monomers; and,optionally, (b) not more than 50% by weight of monomers that are notvinyl acetate and are not within the description of part (a) immediatelyabove but are copolymerizable with said monomers that are within thedescription of said part (a).
 2. A liquid composition according to claim1 additionally comprising a component (C) of alkalinizing alkali metal,ammonium, or both alkali metal and ammonium salt dissolved in thecomposition.
 3. A liquid composition according to claim 2 wherein: (a)there is a concentration of from 0.001 to 30 g/L of component (A); (b)there is a concentration of component (B) that is from 0.001 to 2.0 ppt;and (c) there is a concentration of component (C) that is from 0.5 to 20g/L.
 4. A liquid composition according to claim 3 wherein there is aconcentration of from 0.10 to 30 g/L of component (A) that has aparticle size not more than 1.7 μm.
 5. A liquid composition according toclaim 1, wherein: (a) there is a concentration of from 0.001 to 30 g/Lof component (A); and (b) there is a concentration of component (B) thatis from 0.001 to 2.0 ppt.
 6. A liquid composition according to claim 5wherein there is a concentration of from 0.10 to 30 g/L of component (A)that has a particle size not more than 1.7 μm.
 7. A process forproducing a liquid composition for conditioning metal surfaces prior tophosphate conversion coating treatment thereof, said liquid compositioncontaining an aqueous dispersion comprising the following components:(A) a component of stably dispersed, undissolved solid powder that isconstituted of phosphates that contain at least one divalent ortrivalent metal, the solid powder thereof having a particle size of notmore than 5 μm; and (B) an accelerant component selected from the groupconsisting of the following subgroups: (1) monosaccharides,polysaccharides, and derivatives thereof; (2) orthophosphoric acid,condensed phosphoric acids, and organophosphonic acid compounds; (3)water-soluble polymers that are homopolymers or copolymers of vinylacetate and derivatives of these homopolymers and copolymers; and (4)copolymers and polymers as afforded by the polymerization of: (a) atleast one selection from: (i) monomers, exclusive of vinyl acetate, thatconform to general chemical formula (I):

 where R¹=H or CH₃ and R²=H, C₁ to C₅ alkyl or C₁ to C₅ hydroxyalkyl;and (ii) other α,β-unsaturated carboxylic acid monomers; and,optionally, (b) not more than 50% by weight of monomers that are notvinyl acetate and are not within the description of part (a) immediatelyabove but are copolymerizable with said monomers that are within thedescription of said part (a), said process comprising introducing atleast part of both components (A) and (B) into said composition bygrinding a mixture of a solid material of component (A) and a solutionin water of a material of component (B) and either utilizing saidmixture after grinding as said liquid composition or mixing said mixtureafter grinding with one or more other liquids to form said liquidcomposition.
 8. A process for conditioning a metal surface prior to thephosphate conversion coating treatment thereof by effecting contactbetween said metal surface and a surface conditioning liquid compositionproduced according to claim 7 prior to the formation of a phosphateconversion coating on said metal surface.
 9. A process according toclaim 8 wherein said surface conditioning liquid compositionadditionally comprises dissolved in the composition (a) alkalinizingalkali metal, ammonium, or both alkali metal and ammonium salt or (b) anonionic surfactant, an anionic surfactant, or a mixture thereof, or oneor more components of both (a) and (b).
 10. A process for conditioning ametal surface prior to the phosphate conversion coating treatmentthereof by effecting contact between said metal surface and a surfaceconditioning liquid composition according to claim 6 prior to theformation of a phosphate conversion coating on said metal surface.
 11. Aprocess according to claim 10, wherein prior to the formation of aphosphate conversion coating on the metal surface, the metal surface issimultaneously activated and cleaned by contact with a surfaceconditioning liquid composition that additionally comprises nonionicsurfactant, anionic surfactant, or a mixture thereof.
 12. A process forconditioning a metal surface prior to the phosphate conversion coatingtreatment thereof by effecting contact between said metal surface and asurface conditioning liquid composition according to claim 3 prior tothe formation of a phosphate conversion coating on said metal surface.13. A process according to claim 12, wherein prior to the formation of aphosphate conversion coating on the metal surface, the metal surface issimultaneously activated and cleaned by contact with a surfaceconditioning liquid composition that additionally comprises nonionicsurfactant, anionic surfactant, or a mixture thereof.
 14. A process forconditioning a metal surface prior to the phosphate conversion coatingtreatment thereof by effecting contact between said metal surface and asurface conditioning liquid composition according to claim 2 prior tothe formation of a phosphate conversion coating on said metal surface.15. A process according to claim 14, wherein prior to the formation of aphosphate conversion coating on the metal surface, the metal surface issimultaneously activated and cleaned by contact with a surfaceconditioning liquid composition that additionally comprises nonionicsurfactant, anionic surfactant, or a mixture thereof.
 16. A process forconditioning a metal surface prior to the phosphate conversion coatingtreatment thereof by effecting contact between said metal surface and asurface conditioning liquid composition according to claim 1 prior tothe formation of a phosphate conversion coating on said metal surface.17. A process according to claim 16, wherein prior to the formation of aphosphate conversion coating on the metal surface, the metal surface issimultaneously activated and cleaned by contact with a surfaceconditioning liquid composition that additionally comprises nonionicsurfactant, anionic surfactant, or a mixture thereof.
 18. A processaccording to claim 7 wherein the grinding produces a solid powder ofcomponent (A) that has a particle size not more than 1.7 μm.
 19. Aprocess according to claim 7 wherein one or more additives selected froma group comprising (a) alkalinizing alkali metal, ammonium, or bothalkali metal and ammonium salt dissolved in the composition, and (b)nonionic surfactant, anionic surfactant, or a mixture thereof are addedto the resulting liquid composition.
 20. A process according to claim 7wherein the resulting liquid composition comprises (a) a concentrationof component (A) that is from 0.001 to 30 g/L; and (b) a concentrationof component (B) that is from 0.001 to 2.0 ppt.
 21. A liquid compositionfor conditioning metal surfaces prior to phosphate conversion coatingtreatment thereof, said liquid composition containing an aqueousdispersion comprising the following components: (A) a stably dispersed,undissolved solid powder component that is constituted of phosphatesthat contain at least one divalent or trivalent metal, the solid powderthereof having a particle size of not more than 5 μm; and (B) anaccelerant component selected from the group consisting of the followingsubgroups: (1) water-soluble polymers that are homopolymers orcopolymers of vinyl acetate and derivatives of these homopolymers andcopolymers; and (2) copolymers and polymers as afforded by thepolymerization of: (a) at least one selection from: (i) monomers,exclusive of vinyl acetate, that conform to general chemical formula(I):

 where R¹=H or CH₃ and R²=H, C₁ to C₅ alkyl, or C₁ to C₅ hydroxyalkyl;and (ii) other α,β-unsaturated carboxylic acid monomers; and,optionally, (b) not more than 50% by weight of monomers that are notvinyl acetate and are not within the description of part (a) immediatelyabove but air copolymerizable with said monomers that are within thedescription or said part (a).
 22. A liquid composition according toclaim 21 additionally comprising a component (C) of alkalinizing alkalimetal, ammonium, or both alkali metal and ammonium salt dissolved in thecomposition.
 23. A liquid composition according to claim 21 wherein thesolid powder of component (A) has a particle size not more than 1.7 μm.24. A liquid composition according to claim 21 wherein (a) there is aconcentration of component (A) that is from 0.001 to 30 g/L; and (b)there is a concentration of component (B) that is from 0.001 to 2.0 ppt.25. A liquid composition according to claim 22 wherein (a) there is aconcentration of component (A) that is from 0.001 to 30 g/L (b) there isa concentration of component (B) that is from 0.001 to 2.0 ppt; and (c)there is a concentration of component (C) that is from 0.5 to 20 g/L.